Tarsal-metatarsal joint procedure utilizing fulcrum

ABSTRACT

A technique for correcting a bone deformity, such as a bunion, may be performed using a fulcrum. In some examples, the technique involves inserting a fulcrum between a first metatarsal that is anatomically misaligned with respect to a second metatarsal. The technique further includes preparing an end of the first metatarsal and preparing an end of a medial cuneiform opposing the end of the first metatarsal. In addition, a distal portion of the first metatarsal is moved toward the second metatarsal in a transverse plane, thereby pivoting a proximal portion of the first metatarsal about the fulcrum and reducing an intermetatarsal angle between the first metatarsal and the second metatarsal.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/293,189, filed Feb. 9, 2016. This application is also acontinuation-in-part of U.S. patent application Ser. No. 14/981,335,filed Dec. 28, 2015, which claims the benefit of U.S. ProvisionalApplication No. 62/205,338, filed Aug. 14, 2015. The entire contents ofall these applications are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates generally to devices and methods for positioningand/or preparing bones.

BACKGROUND

Bones, such as the bones of a foot, may be anatomically misaligned. Incertain circumstances, surgical intervention is required to correctlyalign the bones to reduce patient discomfort and improve patient qualityof life.

SUMMARY

Embodiments of the present invention include methods for fixing anorientation of a bone or bones. In general, the method of positioning abone includes the steps of moving a bone from an anatomically misalignedposition to an anatomically aligned position with respect to anotherbone and preparing an end of the bone and a facing end of another bone.In some embodiments, at least one bone end is prepared after the bone ismoved into the aligned position. In some embodiments, the bone isanatomically aligned in more than one plane such that the bone bothtranslates and rotates in response to a moving force.

One embodiment includes a method of correcting a bunion deformity. Themethod includes inserting a fulcrum between a first metatarsal and asecond metatarsal, where the first metatarsal is anatomically misalignedwith respect to the second metatarsal. The method further includespreparing an end of the first metatarsal and preparing an end of amedial cuneiform opposing the end of the first metatarsal. In addition,the method involves moving a distal portion of the first metatarsaltoward the second metatarsal in a transverse plane, thereby pivoting aproximal portion of the first metatarsal about the fulcrum and reducingthe intermetatarsal angle between the first metatarsal and the secondmetatarsal.

In one example, a fulcrum is described for use in a bone realignmentprocedure. The fulcrum includes a body and a handle. The body isconfigured to be inserted in an intermetatarsal space between adjacentmetatarsals. The handle is operatively connected to the body. Theexample specifies that the handle projects at a non-zero degree anglefrom the body to define a tissue retraction space between the handle andthe body.

In another example, a multidimensional fulcrum is described thatincludes a fulcrum body having a length extending from a first end to asecond end, a width, and a thickness. The first end of the fulcrum has afirst thickness and is configured to be inserted into an intermetatarsalspace between adjacent metatarsals of a first size. The second end ofthe fulcrum has a second thickness and is configured to be inserted intoan intermetatarsal space between adjacent metatarsals of a second size.The example specifies that the second thickness is greater than thefirst thickness.

The details of one or more examples are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative of particular embodiments of thepresent invention and, therefore, in no way limit the scope of theinvention. The drawings are not necessarily to scale (unless otherwisestated) and are intended for use in conjunction with the explanations inthe following detailed description. Embodiments of the invention willhereinafter be described with respect to the appended drawings, whereinlike numerals denote like elements.

FIG. 1 is a side perspective view of a bone positioning guide inaccordance with an embodiment of the invention.

FIG. 2 is a side perspective view of a bone engagement member of a bonepositioning guide in accordance with an embodiment of the invention.

FIG. 3A is a side perspective view of a tip of a bone positioning guidein accordance with an embodiment of the invention.

FIG. 3B is a side view of a bone positioning guide with a straight tipin accordance with an embodiment of the invention.

FIG. 3C is a side view of a bone positioning guide with a nonlinear tipin accordance with an embodiment of the invention.

FIG. 4 is an end view of an actuator of a bone positioning guide inaccordance with an embodiment of the invention.

FIG. 5 is a top plan view of a bone preparing guide in accordance withan embodiment of the invention.

FIG. 6A is a perspective view of a bone preparing guide, a spacer, and atissue removing instrument location check member in accordance with anembodiment of the invention.

FIG. 6B is a perspective view of another embodiment of a tissue removinginstrument check location member engaged with a bone preparing guide.

FIG. 7 is a perspective view of a bone preparing guide engaged with aspacer in accordance with an embodiment of the invention.

FIG. 8 is a perspective view of a bone preparing guide engaged with atissue removal instrument location check member in accordance with anembodiment of the invention.

FIG. 9A is a front view of a bone positioning guide on a deformed footin accordance with an embodiment of the invention.

FIG. 9B is a front view of a bone positioning guide on a foot with acorrected alignment in accordance with an embodiment of the invention.

FIG. 10A is a top view of a bone positioning guide on a deformed foot inaccordance with an embodiment of the invention.

FIG. 10B is a top view of a bone positioning guide on a foot with acorrected alignment in accordance with an embodiment of the invention.

FIGS. 11A-C depict a sequence of a bone positioning operation using abone positioning guide on a foot at first, second, and third positionsin accordance with an embodiment of the invention.

FIG. 12A is a front view of a foot with a normal first metatarsalposition.

FIG. 12B is a front view of a foot with an isolated first metatarsalrotation bunion deformity.

FIG. 13A is a top view of a foot with a normal first metatarsalposition.

FIG. 13B is a top view of a foot with an isolated first metatarsaltransverse plane bunion deformity.

FIG. 14A is a side view of a foot with a normal first metatarsalposition.

FIG. 14B is a side view of a foot with an isolated first metatarsalsagittal plane bunion deformity.

FIG. 15A is a perspective view and an enlarged view of a foot.

FIG. 15B is a perspective view of a first metatarsal.

FIG. 16 is a side perspective view of a foot depicting a bonepreparation instrument inserted into a joint.

FIG. 17 is a perspective view of a foot depicting a bone positioningguide on the foot prior to an alignment of a first metatarsal.

FIG. 18 is a perspective view of a foot depicting a bone positioningguide on the foot after an alignment of a first metatarsal.

FIG. 19 is a perspective view of a foot depicting a bone positioningguide on the foot after an alignment of a first metatarsal and aninsertion of a spacer into a joint space.

FIG. 20 is a perspective view of a foot depicting a bone positioningguide on the foot after an alignment of a first metatarsal and apositioning of a bone preparation guide.

FIG. 21A is a perspective view of a foot depicting a bone positioningguide on the foot after an alignment of a first metatarsal and apositioning of a bone preparation guide with pins.

FIG. 21B is another perspective view of a foot depicting a bonepositioning guide on the foot after an alignment of a first metatarsaland a positioning of a bone preparation guide with pins.

FIG. 22 is a perspective view of a foot depicting a bone preparationinstrument preparing a bone of the foot guided by a guide surface of abone preparation guide.

FIG. 23 is a perspective view of a foot depicting a bone positioningguide on the foot and a removal of a bone preparation guide.

FIG. 24 is a perspective view of a foot depicting a bone positioningguide on the foot and pins.

FIG. 25 is a perspective view of a foot depicting a bone positioningguide on the foot and a compression pin.

FIG. 26A is a side perspective view of a foot depicting bone platesacross a joint between first and second bones and a compression pin inaccordance with an embodiment of the invention.

FIG. 26B is a side perspective view of a foot depicting bone platesacross a joint between first and second bones and a compression pin inaccordance with an embodiment of the invention.

FIG. 27 is a side perspective view of a foot depicting bone platesacross a joint between first and second bones in accordance with anembodiment of the invention.

FIG. 28A and FIG. 28B depict examples of anatomically misalignedmetatarsals and metatarsals that have been anatomically aligned usingmethods and/or instruments in accordance with the invention.

FIG. 29A and FIG. 29B depict examples of anatomically misalignedmetatarsals and metatarsals that have been anatomically aligned usingmethods and/or instruments in accordance with the invention.

FIG. 30A illustrates a portion of a foot having a bunion caused by amisaligned first metatarsal relative to a second metatarsal.

FIG. 30B shows an example base compression that can be caused after thefoot of FIG. 30A is anatomically aligned.

FIG. 31 illustrates an example bone positioning operation in which afulcrum is positioned at an intersection between a first bone and asecond bone.

FIG. 32 is a perspective view of one example fulcrum.

FIG. 33 illustrates an example system of different sized fulcrums.

FIG. 34 is a perspective view of another bone positioning guideaccording to an embodiment of the invention.

FIG. 35 illustrates an example configuration of a joint spacer that canallow a bone preparation guide to rotate around the spacer.

FIG. 36A is a perspective view of an example configuration of a bonepositioning guide having an opening with circular cross-sectional shape.

FIG. 36B is a perspective view of the example bone positioning guide ofFIG. 36A shown with the joint spacer from FIG. 35 inserted into theguide.

FIG. 37 is a block flow diagram of an example bone correction techniqueutilizing a fulcrum.

FIG. 38 is a perspective view of a foot showing an example position of afulcrum during a bone correction procedure according to the method ofFIG. 37.

FIGS. 39A and 39B are different perspective views of another examplefulcrum that can be used during a bone correction procedure.

FIG. 40 is an image of the example fulcrum of FIGS. 39A and 39B insertedbetween a first metatarsal and a second metatarsal.

FIG. 41 illustrates an alternative arrangement of surface features thatmay be used on the example fulcrum of FIGS. 39A and 39B.

FIGS. 42A and 42B are perspective and side views, respectively, of anexample fulcrum having two fulcrum bodies.

FIGS. 43A and 43B are perspective and side views, respectively, of anexample multidimensional fulcrum having ends of different dimensions anda unitary body.

DETAILED DESCRIPTION

The following detailed description is exemplary in nature and is notintended to limit the scope, applicability, or configuration of theinvention. Rather, the following description provides practicalillustrations for implementing exemplary embodiments of the disclosure.Examples of constructions, materials, and dimensions are provided forselected elements, and all other elements employ that which is known tothose of ordinary skill in the field of the invention. Those skilled inthe art will recognize that many of the noted examples have a variety ofsuitable alternatives.

Embodiments of the invention include a bone positioning guide and methodof positioning bones in a medical procedure. In an exemplaryapplication, embodiments of the bone positioning guide can be usefulduring a surgical procedure, such as a bone alignment, osteotomy, fusionprocedure, and/or other procedures where one or more bones are to beprepared (e.g., cartilage or bone removal and/or cut). Such a procedurecan be performed, for example, on bones (e.g., adjacent bones separatedby a joint or different portions of a single bone) in the foot or hand,where bones are relatively smaller compared to bones in other parts ofthe human anatomy. In one example, a procedure utilizing an embodimentof the bone positioning guide can be performed to correct an alignmentbetween a metatarsal (e.g., a first metatarsal) and a second metatarsaland/or a cuneiform (e.g., a medial, or first, cuneiform), such as in abunion correction surgery. An example of such a procedure is a Lapidusprocedure (also known as a first tarsal-metatarsal fusion). In anotherexample, the procedure can be performed by modifying an alignment of ametatarsal (e.g., a first metatarsal). An example of such a procedure isa basilar metatarsal osteotomy procedure.

FIG. 1 shows a side perspective view of a bone positioning guide 10 inaccordance with an embodiment of the invention. The bone positioningguide 10 can be useful for positioning a bone (e.g., orientating and/ortranslating) during a medical procedure. In some embodiments, the bonepositioning guide includes a bone engagement member, a tip, a mechanismto urge the bone engagement member and the tip towards each other (e.g.moving the bone engagement member towards the tip, moving the tiptowards the bone engagement member, or moving both simultaneously), andan actuator to actuate the mechanism. When the mechanism is actuated itcauses a first bone engaged with the bone engagement member to move tocorrect an alignment in more than one plane with respect to a secondbone in contact with the tip. In some embodiments, the correction inmore than one plane includes a correction about an axis in a frontalplane.

In the embodiment of FIG. 1, bone positioning guide 10 includes a mainbody member 20 and a shaft 30, and the bone engagement member 40 isconnected to the shaft and the tip 50 is connected to the main bodymember. In general, the main body member 20 can be sized and shaped toclear anatomy or other instrumentation (e.g., pins and guides) whilepositioned on a patient. In the embodiment of FIG. 1, the main bodymember 20 includes a generally C-shaped configuration with a first end60 and a second end 70. In some embodiments, the main body is sized andconfigured to engage bones of a human foot. In addition, although bonepositioning guide 10 is illustrated as being formed of two components,main body member 20 and shaft 30, the guide can be fabricated from morecomponents (e.g., 3, 4, or more) that are joined together to form theguide.

A shaft 30 can be movably connected to the main body member 20 proximateits first end 60. In some embodiments, the shaft 30 includes threads 80that engage with the main body member 20 such that rotation of the shafttranslates the shaft with respect to the main body member. In otherembodiments, the shaft can slide within the main body member and can besecured thereto at a desired location with a set screw. In yet otherembodiments, the shaft can be moved with respect to the main body by aratchet mechanism. In the embodiment shown, the shaft moves along anaxis that intersects the tip 50. In other embodiments, such as thatdescribed with respect to FIG. 34, the shaft 30 and/or bone engagementmember 40 is offset from tip 50.

As shown in FIG. 2, embodiments of the bone positioning device can havea bone engagement member 40. In some embodiments, the bone engagementmember includes a surface 90 configured to contact a bone, such as ametatarsal or a cuneiform. In the embodiment shown, the surface 90 isconcave. Such a surface is adapted to promote surface contact with agenerally cylindrical bone, such as a metatarsal. Other embodiments ofsurface shapes include planar surfaces and V-shaped surfaces. When usinga concave or V-shaped bone engagement member 40, the sidewalls of theconcavity or V-shaped groove may be symmetrical or asymmetrical. In asymmetrical configuration, the bottom of the concavity or groove can becentered between upwardly extending sidewalls configured to receive abone. Each sidewall can extend upwardly to the same height and/or at thesame slope. In the asymmetrical configuration, one sidewall can have adifferent configuration than the opposing sidewall. For example, one ofthe sidewalls may extend upwardly from the bottom of the concavity orgroove to a lower height than the opposing sidewall. As another example,one sidewall may extend upwardly at a different angle than the opposingsidewall. The asymmetrical configuration can be useful for applying aforce that is biased laterally instead of only being linear toward tip50.

In some embodiments, bone engagement member 40 includes a pin or aclamp. Independent of whether bone engagement member 40 includes suchpin or clamp, the bone engagement member can engage an anatomicalfeature of a bone, such as a ridge (e.g., a medial ridge of a firstmetatarsal). In such embodiments, the engagement generally prohibitsrotational movement of the bone with respect to the bone engagementmember. In other embodiments, bone may be allowed to rotate with respectto the bone engagement member.

In the embodiment shown, the bone engagement member 40 is provided on anend of the shaft 30. In the embodiment of the shaft shown having threads80, the bone engagement member 40 can be rotatably coupled to the shaft30. In such embodiments, as the shaft is rotated relative to the mainbody member the bone engagement member 40 may or may not rotate withrespect to the main body member even as it translates with respect tothe main body member along with the shaft 30 and rotates with respect tothe shaft. The bone engagement member may oscillate about the shaft 30,but generally does not rotate with respect to bone after contact withthe bone.

FIGS. 3A-C depict a tip 50 of bone positioning guide 10, which can be ata second end 70 of the main body member opposite the first end. The tip50 can be useful for contacting a bone, generally a bone distinct from abone contacting the bone engagement member. For example, if the boneengagement member is in contact with a first metatarsal, the tip can bein contact with a metatarsal other than the first metatarsal (e.g., thesecond, third, fourth, or fifth metatarsal). In some embodiments, thetip is tapered to facilitate percutaneous insertion and contact withbone. The tip can also include a textured surface 100, such as serrated,roughened, cross-hatched, knurled, etc., to reduce slippage between thetip and bone. In the embodiment shown, the tip further includes a stop110 to limit a depth of insertion. The shape of the tip can beconfigured to stably contact bone. For example, FIG. 3B shows a sideview of the bone positioning guide with a generally straight tip 50,while FIG. 3C shows a side view of the bone positioning guide with anonlinear tip 50 (e.g., a tip that is angled or curved). In someembodiments, the tip is configured to restrict translational movementbetween it and a bone, but to allow rotational movement between it andthe bone.

As shown in FIG. 4, bone positioning guide 10 can also include anactuator (e.g., a knob or a handle) 120 to actuate the mechanism, inthis embodiment associated with the shaft. In the embodiment shown, theactuator can be useful for allowing a user to rotate the shaft withrespect to the main body member 20. Also as shown in FIG. 4, theactuator, shaft, and bone engagement member may include a cannulation130 to allow the placement of a fixation wire (e.g., K-wire) throughthese components and into contact with or through a bone engaged withthe bone engagement member. For example, the fixation wire can be placedinto the bone engaged with bone engagement member 40 to fix the positionof the bone engagement member with respect to the bone. In anotherexample, the fixation wire can be placed through the bone in contactwith the bone engagement member and into an adjacent bone to maintain abone position of the bone in contact with the bone engagement member andthe adjacent bone.

In other embodiments, the mechanism to urge the bone engagement memberand the tip towards each other can include a tenaculum or tongstructure. In such embodiments, the guide can include a first shaftpivotably connected to a second shaft. A first end of each shaft caninclude an actuator, such as a handle. A second end of the first shaftcan include a bone engagement member, as described above. And a secondend of the second shaft can include a tip, as described above. In use,the actuator can be actuated (e.g., squeezed together) to move the boneengagement member and the tip closer together to position bone. Otherembodiments of this type may include another set of shafts and anotherpivoting connection such that the bone engagement member and tiptranslate towards each other when the actuator is actuated.

In other embodiments, the mechanism to urge the bone engagement memberand the tip towards each other can include a rack and pinion structure.In such embodiments, the rack can include a tip, as described above. Andthe pinion can include a bone engagement member, as described above, andan actuator (e.g., a knob). In use, the actuator can be actuated (e.g.,turned about an axis generally perpendicular to a direction of travel)to move the bone engagement member and the tip closer together toposition bone.

Embodiments of the bone positioning guide may include any suitablematerials. In certain embodiments, the bone positioning guide isfabricated from a radiolucent material such that it is relativelypenetrable by X-rays and other forms of radiation, such asthermoplastics and carbon-fiber materials. Such materials are useful fornot obstructing visualization of bones using an imaging device when thebone positioning guide is positioned on bones.

Embodiments of the bone positioning guide can be useful in operation forpositioning a bone or bones during a medical procedure. Bone positioningcan be useful, for instance, to correct an anatomical misalignment ofbones and maintain an anatomically aligned position, such as in a bonealignment and/or fusion procedure. In some embodiments, the bonepositioning guide is capable of reducing an angle between the firstmetatarsal and the second metatarsal from over 10 degrees (e.g., up toabout 35 degrees) to about 10 degrees or less (e.g., to about 1-5degrees), including to negative angles of about −5 degrees. In someembodiments, the bone positioning guide is also capable of rotating thefirst metatarsal about its long axis with respect to the medialcuneiform from a rotational angle of over 4 degrees to a rotationalangle of less than 4 degrees (e.g., to about 0 to 2 degrees).

In some embodiments, a bone preparation guide may be provided tofacilitate the preparation of a bone. The bone preparation guide can beprovided with a bone positioning guide, or either device can be providedor used independently. An example of a bone preparation guide 150 isshown in FIG. 5. In some embodiments, the bone preparation guide 150includes a body 154 defining a first guide surface 160 to define a firstpreparing plane and a second guide surface 164 to define a secondpreparing plane. A tissue removing instrument (e.g., a saw, rotary bur,osteotome, etc., not shown) can be aligned with the surfaces to removetissue (e.g., remove cartilage or bone and/or make cuts to bone). Thefirst and second guide surfaces 160, 164 can be spaced from each otherby a distance, (e.g., between about 2 millimeters and about 10millimeters, such as between about 4 and about 7 millimeters). In theembodiment shown, the first and second guide surfaces are parallel, suchthat cuts to adjacent bones using the guide surfaces will be generallyparallel.

In some embodiments, as shown in FIG. 5, a first facing surface 166 ispositioned adjacent the first guide surface 160 and/or a second facingsurface 168 is positioned adjacent the second guide surface 164. In suchembodiments, the distance between the first guide surface and the firstfacing surface defines a first guide slot, and the distance between thesecond guide surface and the second facing surface defines a secondguide slot. Each slot can be sized to receive a tissue removinginstrument to prepare the bone ends. The first and second slots may beparallel or skewed. In the illustrated embodiment, the facing surfaceseach contain a gap, such that the surface is not a single, continuoussurface. In other embodiments, the facing surfaces can be a single,continuous surface lacking any such gap.

An opening 170 can be defined by the body 154 between the first andsecond guide surfaces. The opening can be an area between the guidesurfaces useful for allowing a practitioner to have a visual path tobones during bone preparation and/or to receive instruments. In theembodiment shown, the opening extends across the body and a distancefrom a surface 172 opposite of the first facing surface 166 to a surface174 opposite of the second facing surface 168.

The embodiment shown also includes a first end 176 extending from thebody 154 in a first direction and a second end 178 extending from thebody in a second direction. The second direction can be different thanthe first direction (e.g., an opposite direction). As shown, each of thefirst end and the second end can include at least one fixation aperture180 configured to receive a fixation pin (not shown in FIG. 5) to securethe guide to a bone. As shown, such apertures may extend through the endat a vertical or skewed angle relative to a top surface of the guide.

The bone preparation guide 150 can also include a first adjustablestabilization member 182 engaged with the first end 176. In someembodiments, the bone preparation guide can include a second adjustablestabilization member 184 engaged with the second end 178. Each of themembers can be threaded and engage a threaded aperture defined by theends. The elevation of each end can be adjusted with respect to a boneby adjusting the stabilization member. In some embodiments, as shown,the stabilization members are cannulated such that they can receive afixation pin.

As shown in FIGS. 6A and 7, the bone preparation guide can also includea spacer 188 extending downward from the body 154 and configured to beplaced into a joint. In some embodiments, the spacer 188 is selectivelyengageable with the body. The spacer can have a first portion 190configured to extend into a joint space and a second portion 192engageable with the body 154. In the embodiment shown, the spacer can bereceived within opening 170, such that the spacer extends from the bodyin between the first and second guide surfaces. Such a spacer can beuseful for positioning the body at a desired position with respect to ajoint and for properly positioning the guide with respect to bones to becut in more than one plane (e.g., three planes selected from more thanone of a frontal plane, a transverse plane, and a sagittal plane). Thedistance between the spacer and the first guide surface can define alength of tissue removal (e.g., bone or cartilage to be cut) from afirst bone, and the distance between the spacer and the second guidesurface can define a length of tissue removal (e.g., bone or cartilageto be cut) from a second bone.

As shown in FIGS. 6A/B and 8, the bone preparation guide can alsoinclude a tissue removal location check member 194 engageable with thebody 154 and configured to extend to a first bone and a second bone. Thetissue removal location check member can have a first portion 196configured to extend into contact with first and second bones and asecond portion 198 engageable with the body. In the embodiments shown inFIGS. 6A and 8, the tissue removal location check member extends fromthe body at both the first and second guiding surfaces. In otherembodiments, such as the embodiment shown in FIG. 6B, separate tissueremoval location check members are provided for independent insertioninto respective slots of the guide. Accordingly, embodiments of tissueremoval location check members are useful for allowing a practitioner tosee where a tissue removing instrument guided by the surfaces willcontact the bone to be prepared.

Embodiments of the bone preparation guide can be useful in operation forguiding a preparation of a bone or bones at a targeted anatomy. Bonepreparation can be useful, for instance, to facilitate contact betweenleading edges of adjacent bones, separated by a joint, or differentportions of a single bone, separated by a fracture, such as in a bonealignment and/or fusion procedure. A bone may be prepared using one ormore bone preparation techniques. In some applications, a bone isprepared by cutting the bone. The bone may be cut transversely toestablish a new bone end facing an opposing bone portion. Additionallyor alternatively, the bone may be prepared by morselizing an end of thebone. The bone end can be morselized using any suitable tool, such as arotary bur, osteotome, or drill. The bone end may be morselized bymasticating, fenestrating, crushing, pulping, and/or breaking the boneend into smaller bits to facilitate deformable contact with an opposingbone portion.

Embodiments of the present invention also include methods fortemporarily fixing an orientation of a bone or bones, for example, priorto or in conjunction with permanently fixing the orientation of the boneor bones. In general, the method of positioning a bone includes thesteps of moving a bone from an anatomically misaligned position to ananatomically aligned position with respect to another bone and preparingan end of the moved bone and a facing end of another bone. In someembodiments, the end of at least one of the moved bone and the otherbone is prepared after moving the bone into the aligned position. Incertain embodiments, the bone is anatomically aligned in more than oneplane with respect to another bone by applying a force to one bone at asingle location, such that the bone both translates and rotates inresponse to the force. In certain embodiments, the moving step can beaccomplished with a bone positioning device and/or the preparing stepcan be accomplished with a bone preparation guide, as described herein.In other embodiments, the moving step can be accomplished by a clinicianphysically grasping a bone, either through direct contact with the boneor indirectly (e.g., by inserting a K-wire, grasping with a tenaculum,or the like), and moving his hand to move the bone. In theseapplications, a fulcrum may be used to control movement of the bone, asalso described herein.

FIGS. 9A-B depict fontal views of a bone positioning guide 10 on a foot200 having a first metatarsal 210, a medial cuneiform 220, a secondmetatarsal 292, and a third metatarsal 294. FIG. 9A depicts a foot 200with an uncorrected bunion deformity, while FIG. 9B depicts the foot 200with an alignment corrected by the bone positioning guide 10. Solid lineL1 represents the starting location of the bone positioning guide 10 anddotted line L2 represents the finishing location of the bone positioningguide. As shown, as the bone positioning guide 10 is actuated it rotateswith the first metatarsal 210 about an axis extending through thefrontal plane as it pushes the first metatarsal 210 laterally in thetransverse plane and plantarly in the sagittal plane. Accordingly, inthis example, the position of the first metatarsal 210 is corrected withrespect to the second metatarsal 292 generally in three planes byactuating a single bone positioning guide 10 to urge a bone engagementmember 40 toward a tip 50. FIG. 10A shows a top view of a foot 200 withan uncorrected bunion deformity, while FIG. 10B shows a top view of thefoot 200 with an alignment corrected by the bone positioning guide 10,emphasizing the rotational correction in the frontal plane and thelateral correction in the transverse plane.

FIGS. 11A-C show three sequential images of a bone positioning guide 10on a foot 200 positioning a first metatarsal 210 with respect to asecond metatarsal 292. FIG. 11A represents the beginning of theprocedure, FIG. 11B the middle, and FIG. 11C the end. The orientation ofthe pins 270 is useful for visualizing the amount of rotation of thefirst metatarsal 210 in each image. With respect to FIGS. 11A-C, it canbe seen the bone positioning guide 10 and the first metatarsal 210 arerotating in the frontal plane in response to actuation of bonepositioning guide 10. Further, the angle between the first metatarsal210 and second metatarsal 292 is reduced, as the space that can be seenbetween the first and second metatarsals in FIG. 11A is eliminated inFIG. 11C.

Each of the three potential planes of deformity will now be described inisolation. FIGS. 12A and 12B show frontal plane views of a foot 200. InFIG. 12A, the foot 200 is normal, while in FIG. 12B the foot is depictedwith an uncorrected bunion deformity showing an isolated axial rotationof the first metatarsal 210. Solid line L3 indicates the alignment ofthe first metatarsal 210 relative to ground, while dotted line L4 inFIG. 12B indicates the extent of axial rotation in the frontal plane.

FIGS. 13A and 13B show transverse plane views of a foot 200. In FIG.13A, the foot 200 is normal, while in FIG. 13B the foot is depicted withan uncorrected bunion deformity showing an isolated transverse planefirst metatarsal 210 deviation. Solid line L5 indicates the alignment ofthe second metatarsal 292 and solid line L6 indicates the properalignment of the first metatarsal 210 relative to the second metatarsal292. The angle between these two lines forms the intermetatarsal angle(IMA). Dotted line L7 in FIG. 13B indicates the extent of transversedeviation.

FIGS. 14A and 14B show sagittal plane views of a foot 200. In FIG. 14A,the foot 200 is normal, while in FIG. 14B the foot is depicted with anuncorrected bunion deformity showing an isolated sagittal deviation ofthe first metatarsal 210. Solid line L8 indicates the proper alignmentof the first metatarsal 210, while dotted line L9 in FIG. 14B indicatesthe extent of sagittal deviation.

A specific embodiment of a method in accordance with an embodiment ofthe invention includes the steps of engaging a bone engagement memberwith a first bone, placing a tip of the bone positioning guide inapposition to a second bone, the second bone being different from thefirst bone, and moving the bone engagement member with respect to thetip to change the position of the first bone with respect to the secondbone in more than one plane. In some embodiments, after alignment, atleast one of an end of the first bone and a facing end of a third boneare prepared (e.g., only the end of the first bone or both the end ofthe first bone and the end of the second bone), optionally using apreparation guide.

In some embodiments, the method includes the step of mobilizing a jointfor a corrective procedure. For example, after creating surgical accessto the joint and before moving the bones into an aligned position,tissue can be released to allow a bone, such as a metatarsal, to rotatefreely. In some embodiments, obstructing bone may be excised (e.g., adorsolateral flare of the metatarsal base, a plantar flare of themetatarsal base (sometimes referred to as a plantar condyle), part of anend of a metatarsal facing a cuneiform, or osteophyte) to furtherpromote free rotation by creating relatively flat surfaces with respectto a frontal plane. An example of a dorsolateral flare F on a firstmetatarsal 210 of a foot 200 is shown in FIG. 15A. An example of aplantar flare PF on a first metatarsal 210 is shown in FIG. 15B. FIG.15B also depicts a medial ridge MR, which, in some embodiments, can beengaged by the bone engaging member of a bone positioning guide.

Embodiments of methods in accordance with the invention can also includesteps performed after preparing the ends of the bones. For example, theends of the bones may be placed in apposition and optionally compressedtogether and the position of the bones can be fixed with one or morebone fixation devices (e.g., compressing bone screw, bone plate, bonestaple, external fixator, intramedullary implant or nail) prior to aclosing of the surgical access to the joint.

An exemplary method will now be described with respect to FIGS. 16-27depicting a foot 200 having a first metatarsal 210, a medial cuneiform220, and a second metatarsal 292. Note, unless otherwise indicated, thesteps described need not be carried out in the order described.

After customary surgical preparation and access, a bone preparationinstrument 296 can be inserted into the joint (e.g., firsttarsal-metatarsal joint) to release soft tissues and/or excise theplantar flare from the base of the first metatarsal 210, as shown inFIG. 16. Excising the plantar flare may involve cutting plantar flareoff the first metatarsal 210 so the face of the first metatarsal isgenerally planar. This step helps to mobilize the joint to facilitate adeformity correction. In some embodiments, the dorsal-lateral flare ofthe first metatarsal may also be excised to create space for thedeformity correction (e.g., with respect to rotation of the firstmetatarsal). In certain embodiments, a portion of the metatarsal basefacing the medial cuneiform can be removed during this mobilizing step.

An incision can be made and a tip 50 of a bone positioning guide 10 canbe inserted on the lateral side of a metatarsal other than the firstmetatarsal 210, such as the second metatarsal 292. As shown in FIG. 17,the tip can be positioned proximally at a base of the second metatarsal292 and a third metatarsal 294 interface. A surface of a bone engagementmember 40 can be placed on the proximal portion of the first metatarsal210. In some embodiments, the bone engagement member engages a medialridge of the first metatarsal 210. As shown, the body 20 of thepositioning guide can be generally perpendicular to the long axis of thesecond metatarsal 292.

As depicted in FIG. 18, the actuator 120 can be actuated to extend theshaft 30 to reduce the angle (transverse plane angle between the firstmetatarsal and the second metatarsal) and rotate the first metatarsalabout its axis (frontal plane axial rotation). The first metatarsal 210can be properly positioned with respect to the medial cuneiform 220 bymoving the bone engagement member 40 with respect to the tip 50. In someembodiments, such movement simultaneously pivots the first metatarsalwith respect to the cuneiform and rotates the first metatarsal about itslongitudinal axis into an anatomically correct position to correct atransverse plane deformity and a frontal plane deformity. In certainembodiments, body 20 rotates in a generally lateral direction duringthis step. In some embodiments, fixation pins (not shown in FIG. 18) canbe inserted into the bones prior to the positioning step (e.g., freehandor using apertures in the guide as a template), and can be used toimpart additional force (transverse, sagittal, and/or frontal planerotational) to the first metatarsal 210, if desired. The bonepositioning guide 10 can hold the desired position of the firstmetatarsal 210 with respect to the second metatarsal 292. After thedesired correction is achieved, a fixation wire 298 can be insertedthrough a cannulation in the shaft 30 and driven into the firstmetatarsal 210 and the second metatarsal 292 to hold the correctedposition.

As depicted in FIG. 19, a joint spacer 188 can be positioned within thejoint between the first metatarsal and the medial cuneiform.

As shown in FIG. 20, a bone preparation guide 150 can be placed over thejoint spacer 188 and engaged with the joint spacer to set a position andorientation of the bone preparation guide relative to the joint. Asshown, the bone preparation guide 150 can be positioned proximal to thebone positioning guide 10 in longitudinal alignment with the long axisof the first metatarsal 210 and the medial cuneiform 220, generally onthe dorsal or dorsal-medial surface. In other embodiments, the spacer188 is positioned after the guide 150 is provisionally placed on thebones. In yet other embodiments, bone preparation guide 150 and jointspacer 188 are placed simultaneously. In still other embodiments, bonepreparation guide 150 is placed on the bones without using joint spacer188 to aid with positioning.

As depicted in FIGS. 21A and 21B, one or more fixation pins 270 can beinserted into apertures of the bone preparation guide 150 to secure theguide to the first metatarsal 210 and the medial cuneiform 220. Asshown, some pins 270 can be inserted at an angle or in a convergingorientation to help prevent movement of the bone preparation guide 150during a tissue removing step. As shown, two of the pins 270, one on thefirst metatarsal and one on the medial cuneiform, are parallel to allowthe bone preparation guide 150 to be removed from the foot withoutremoving all the pins. After insertion of the pins 270, the spacer 188can optionally be removed in embodiments having a selectively engageablespacer (e.g., a joint spacer 188 that is physically removable from bonepreparation guide 150).

In some embodiments, the location of the intersection of the tissueremoving instrument and the bone to be prepared is confirmed before bonepreparation. In one embodiment, a tissue removing instrument locationcheck member can be engaged with the preparation guide to visuallyconfirm where a tissue removal instrument will contact the bone. Inanother embodiment, a tissue removal instrument is engaged with thepreparation guide to visually confirm where the instrument will contactthe bone. In either embodiment, such visual confirmation can include theuse of an imaging device, such as an X-ray. If the position of thepreparation guide is correct, additional fixation pins may be insertedthrough the apertures (e.g., angled apertures) to further fix theposition of the preparation guide with respect to the first metatarsaland the medial cuneiform. In some embodiments, the spacer is reattachedprior to further bone preparation steps.

In some embodiments, the end of the first metatarsal 210 facing themedial cuneiform 220 can be prepared with a tissue removing instrument296 guided by a guide surface of bone preparation guide 150 (e.g.,inserted through a slot defined by a first guide surface and a firstfacing surface). Additionally or alternatively, the end of the firstmetatarsal 210 facing the medial cuneiform 220 can be prepared bymorselizing the end of the first metatarsal. In some embodiments, thefirst metatarsal 210 end preparation is done after the alignment of thebones, e.g., by actuating bone positioning guide 10 before preparing theend of first metatarsal 210. In other embodiments, the first metatarsal210 end preparation is done before the alignment of the bones, e.g., bypreparing the end of the first metatarsal 210 before actuating bonepositioning guide 10.

In addition, as shown in FIG. 22, the end of the medial cuneiform 220facing the first metatarsal 210 can be prepared with the tissue removinginstrument 296 guided by a guide surface of bone preparation guide 150(e.g., inserted through a slot defined by a second guide surface and asecond facing surface). Additionally or alternatively, the end of themedial cuneiform 220 facing the first metatarsal 210 can be prepared bymorselizing the end of the medial cuneiform. In some embodiments, themedial cuneiform 220 end preparation is done after the alignment of thebones. In yet other embodiments, the medial cuneiform 220 endpreparation is done before the alignment of the bones. In embodimentsthat include cutting bone or cartilage, the cuneiform cut and themetatarsal cut can be parallel, conforming cuts. In the specificembodiment shown in FIG. 22, a saw blade can be inserted through a firstslot to cut a portion of the medial cuneiform and the saw blade can beinserted through a second slot to cut a portion of the first metatarsal(e.g., in some embodiments the medial cuneiform can be cut before thefirst metatarsal). Accordingly, in the embodiment shown, the cuts toboth the first metatarsal and the medial cuneiform were preformed afterthe first metatarsal was positioned.

Any angled/converging pins can be removed and the bone preparation guide150 can be lifted off the parallel pins 270, as shown in FIG. 23. Theparallel pins can be referred to as “reference pins” which can serve asa reference in later steps to ensure that the corrected alignment of thefirst metatarsal 210 has been maintained. The joint spacer can also beremoved before, after, or simultaneously with the bone preparationguide. In some embodiments, the bone positioning guide 10 is alsoremoved from the foot.

The tissue (e.g., bone or cartilage slices) from the first metatarsaland the medial cuneiform can be removed from the joint site and thejoint surfaces can be fenestrated, if desired. If the bone positioningguide was taken off the foot, it can be put back on, as shown in FIG.24, before the additional steps discussed below.

After preparation, the ends of the two bones can be placed in appositionand optionally compressed together by provisionally fixating the joint.For example, the two bones may be placed in apposition by placing thecut and/or morselized end of the first metatarsal 210 in abutment withthe cut and/or morselized end of the medial cuneiform 220. In someexamples, the cut and/or morselized end of the first metatarsal 210 isplaced adjacent to, and optionally in contact with, the cut and/ormorselized end of the medial cuneiform 220.

As shown in FIG. 25, a compression pin, such as a threaded olive pin 300can be inserted through the first metatarsal 210 and into the medialcuneiform 220 to provide compression and provisional fixation betweenthe first metatarsal and the medial cuneiform. Additional compressionpins can be inserted to provide additional stability. As shown, theparallel reference pins should be aligned during this step. In someembodiments, a practitioner checks for alignment of the parallelreference pins prior to insertion of the compression pin, and, if theyare not aligned, adjusts the position of the first metatarsal untildesired alignment is achieved.

Although they can be left in place, in some embodiments the parallelreference pins and bone positioning guide can be removed and a bonefixation device (e.g., two bone plates positioned in different planes,as shown) can be applied to stabilize the joint for fusion. FIG. 26Ashows a first bone plate 310 positioned on a dorsal-medial side of thefirst metatarsal and medial cuneiform and a second bone plate 320positioned on a medial-plantar side of the first metatarsal and themedial cuneiform. In other embodiments, such as the embodiment shown inFIG. 26B, the second bone plate 320 can be a helical bone platepositioned from a medial side of the cuneiform to a plantar side of thefirst metatarsal across the joint space. The plates can be applied withthe insertion of bone screws. Example bone plates that can be used asfirst bone plate 310 and/or second bone plate 320 are described in USPatent Publication No. US2016/0192970, titled “Bone Plating System andMethod” and filed Jan. 7, 2016, which is incorporated herein byreference.

As shown in FIG. 27, the compression pin can be removed and the incisioncan be closed.

FIGS. 28 A/B and 29A/B include examples of anatomically misalignedmetatarsals and metatarsals that have been anatomically aligned usingmethods and/or instruments in accordance with the invention. FIG. 28Ashows a left foot pre-operation and post-operation, while FIG. 28B showsa right foot pre-operation and post-operation. As can be seen from acomparison of the pre-operative images to the post-operative images, thepatients' intermetatarsal angle (IMA) was significantly reduced. FIGS.29A and 29B show the correction of an axial rotation in a frontalrotational plane. FIG. 29A shows a pre-operative image and apost-operative image of a right foot. Drawings of a metatarsal 210 arealso provided to illustrate the rotation. The rotation of the metatarsalcan be seen by the position of sesamoid bones 400, which are depicted ashaving been rotated under the first metatarsal 210 in the post-operativedrawing. FIG. 29B shows pre-operative views of a left foot 200 and aright foot 200. Again, by comparing the location of the sesamoid bones400 with respect to a reference location, such as ground, the plantersurface of the foot, and/or a cuneiform, it can be seen this patient'smetatarsal is rotated out of alignment.

Methods in accordance with embodiments of the invention can be usefulfor positioning a bone or bones. Bone positioning can be useful, forinstance, to correct an anatomical misalignment of bones and maintain ananatomically aligned position, such as in a bone alignment and/or fusionprocedure. In some embodiments, an “anatomically aligned position” meansthat an angle of a long axis of a first metatarsal relative to a longaxis of a second metatarsal is about 10 degrees or less in thetransverse plane or sagittal plane. In certain embodiments, anatomicalmisalignment can be corrected in both the transverse plane and thefrontal plane. In the transverse plane, a normal intermetatarsal angle(“IMA”) between a first metatarsal and a second metatarsal may be lessthan about 9 degrees (e.g., less than 6 degrees). An IMA of betweenabout 6 degrees and about 13 degrees (e.g., between about 9 degrees andabout 13 degrees) may be considered a mild or moderate misalignment ofthe first metatarsal relative to the second metatarsal. An IMA ofgreater than about 16 degrees may be considered a severe misalignment ofthe first metatarsal relative to the second metatarsal. In someembodiments, methods in accordance with the invention are capable ofanatomically aligning the bone(s) by reducing the IMA from over 10degrees to about 10 degrees or less (e.g., to an IMA of less than 6degrees, such as to an IMA of about 1-5 degrees), including to negativeangles of about −5 degrees or until interference with the secondmetatarsal, by positioning the first metatarsal at a different anglewith respect to the second metatarsal.

With respect to the frontal plane, a normal first metatarsal will bepositioned such that its crista prominence is generally perpendicular tothe ground and/or its sesamoid bones are generally parallel to theground and positioned under the metatarsal. This position can be definedas a metatarsal rotation of 0 degrees. In a misaligned first metatarsal,the metatarsal is axially rotated between about 4 degrees to about 30degrees or more. In some embodiments, methods in accordance with theinvention are capable of anatomically aligning the metatarsal byreducing the metatarsal rotation from about 4 degrees or more to lessthan 4 degrees (e.g., to about 0 to 2 degrees) by rotating themetatarsal with respect to the medial cuneiform.

While various embodiments of bone positioning and preparing guidesystems and methods have been described, it should be appreciated thatthe concepts of the disclosure can be altered in practice, e.g., basedon the needs of the clinician, the patient undergoing the bonerepositioning procedure, the specific anatomy being treated, and/or thetarget clinical outcome. As one example, the described systems andtechniques may be modified to utilize a fulcrum about which rotationand/or pivoting of one bone relative to another bone occurs, e.g., withor without use of bone positioning guide 10. The fulcrum can establishand/or maintain space between adjacent bones being moved, e.g.,compressed between bone engagement member 40 and tip 50 when using bonepositioning guide 10, preventing lateral translation or base shift ofthe bones during rotation and/or pivoting.

FIG. 30A illustrates a portion of a foot having a bunion caused by amisaligned first metatarsal 210 relative to second metatarsal 292. FIG.30B shows the foot of FIG. 30A after being anatomically aligned tocorrect the misalignment using bone positioning guide 10. As shown,first metatarsal 210 has been rotated counterclockwise in the frontalplane (from the perspective of a patient, clockwise from the perspectiveof a frontal observer) and also pivoted in the transverse plane (e.g.,such that the angle 350 between the first metatarsal 210 and secondmetatarsal 292 is reduced). Rotation and pivoting of first metatarsal210 can cause the base 352 of first metatarsal 210 to shift relative tomedial cuneiform 220. In general, it is desirable that the offset 354Abetween first metatarsal 210 and medial cuneiform 220 be reduced to zero(e.g., such that there is substantially no offset) after rotation andpivoting. As shown in the illustrated application of FIG. 30B, however,the base 352 of first metatarsal 210 abutting medial cuneiform 220 hasshifted toward second metatarsal 292. This results in a transverseoffset 354B of first metatarsal 210 toward second metatarsal 292,causing base compression between first metatarsal 210 and secondmetatarsal 292.

To help avoid the base shift and offset 354B observed in FIG. 30B, aclinician can insert a fulcrum in the notch between first metatarsal 210and second metatarsal 292 at the base of the metatarsals (e.g., adjacentrespective cuneiform) before actuating bone positioning guide 10. Thefulcrum can provide a point about which first metatarsal 210 can rotateand/or pivot while helping minimize or avoid base compression betweenthe first metatarsal and the second metatarsal. In addition, use of thefulcrum may cause first metatarsal 210 and medial cuneiform 220 to bebetter angled relative to the guide slots of bone preparation guide 150(once installed), providing a better cut angle through the guide slotsthan without use of the fulcrum. This can help reduce or eliminateunwanted spring-back, or return positioning, of first metatarsal 210after removing bone positioning guide 10 (in instances in which bonepositioning guide 10 is used with the fulcrum).

FIG. 31 illustrates a bone positioning operation in which a fulcrum 356is positioned at an intersection between a first bone and a second bone,where the first bone is being realigned relative to the second bone. Inparticular, FIG. 31 illustrates fulcrum 356 being positioned betweenfirst metatarsal 210 and second metatarsal 292. Fulcrum 356 may bepositioned distally of bone preparation guide 150 between firstmetatarsal 210 and second metatarsal 292 as shown in FIG. 31 or, inother applications, proximally of the guide (e.g., at the ends of thefirst and second metatarsals abutting the medial and intermediatecuneiform bones, respectively). In still other examples, fulcrum 356 canbe positioned in the intermetatarsal space between first metatarsal 210and second metatarsal 292 without using bone preparation guide 150.

When used, the clinician can insert fulcrum 356 between first metatarsal210 and second metatarsal 292 (or other adjacent bones, when notperforming a metatarsal realignment) at any time prior to moving thefirst metatarsal (e.g., by actuating bone positioning guide 10 or othermeans of manipulating the bone). In different embodiments, fulcrum 356can be inserted between first metatarsal 210 and second metatarsal 292before or after inserting joint spacer 188 and/or placing bonepreparation guide 150 over the joint being operated upon. In oneembodiment, the clinician prepares the joint being operated upon torelease soft tissues and/or excise the plantar flare from the base ofthe first metatarsal 210, as discussed above. Either before or afterinstalling bone positioning guide 10 over adjacent bones, for examplewith bone engagement member 40 positioned in contact with the medialridge of the first metatarsal 210 and tip 50 positioned in contact withsecond metatarsal 292, the clinician inserts fulcrum 356 at the jointbetween the first metatarsal and the second metatarsal. The cliniciancan subsequently actuate bone positioning guide 10 (e.g., rotate knob120). In the case of a left foot as shown in FIG. 31, actuation of bonepositioning guide 10 causes the first metatarsal 210 to rotatecounterclockwise in the frontal plane (from the perspective of apatient) and also pivot in the transverse plane about the fulcrum. Inthe case of a right foot (not shown), actuation causes the firstmetatarsal to rotate clockwise in the frontal plane (from theperspective of a patient) and also pivot in the transverse plane aboutthe fulcrum. Thus, for both feet, actuation of bone positioning guide 10can supinate the first metatarsal in the frontal plane and pivot thefirst metatarsal in the transverse plane about fulcrum 356. While use offulcrum 356 can minimize or eliminate base compression between adjacentbones being operated upon, in other embodiments as discussed above, thedescribed systems and techniques can be implemented without using thefulcrum.

In instances in which fulcrum 356 is used, any suitable mechanicalinstrument that maintains a spacing between adjacent bones can be usedfor the fulcrum. FIG. 32 is a perspective view of one example instrumentthat can be used as fulcrum 356. In this embodiment, fulcrum 356 has agenerally rectangular shape and tapers in thickness along at least aportion of the length from the trailing end 358 to the leading end 360.Fulcrum 356 may be sized sufficiently small so that it does notinterfere with placement of bone preparation guide 150 on the jointbeing worked upon. In some embodiments, the clinician is provided asystem containing multiple different size and/or shape fulcrums andallowed to choose the specific size and/or shape fulcrum desired for thespecific procedure being performed. FIG. 33 illustrates an example kitor system of different sized fulcrums, labeled with exemplary “width xthickness” sizes, that may be provided to a clinician in such anembodiment. In some examples, fulcrum 356 has a width ranging from 5millimeters to 15 millimeters (e.g., about 6 millimeters to about 10millimeters) and a thickness ranging 1 millimeter to 12 millimeters(e.g., about 2 millimeters to about 3 millimeters), although fulcrumswith different dimensions can be used.

While FIGS. 32 and 33 illustrate one example style of fulcrum, othermechanical instruments providing a fulcrum functionality can be usedwithout departing from the scope of the disclosure. For instance, asalternative examples, a surgical pin or rod, a screw driver head/shaft,an osteotome, or a retractor may be used as fulcrum 356. Depending onthe instrument used as a fulcrum, the fulcrum may have a variety ofcross-sectional shapes, such as a generally polygonal shape (e.g.,square, hexagonal), a generally arcuate shape (e.g., circular,elliptical), or combinations of polygonal and arcuate shapes.

As discussed above, bone positioning guide 10 can have a variety ofdifferent configurations, including a configuration in which boneengagement member 40 is laterally offset from tip 50. FIG. 34 is aperspective view of bone positioning guide 10 showing an examplearrangement in which bone engagement member 40 is laterally offset fromtip 50. In this embodiment, the first end 60 of main body member 20 islaterally offset from an axis 362 extending through shaft 30 and ageometric center of bone engagement member 40. In particular, in theillustrated configuration, tip 50 is offset laterally in the directionof the cuneiform relative to bone engagement member 40. As a result,when bone positioning guide 10 is actuated, e.g., by rotating knob 120,a moment can be created by the offset tip. This can cause the end of thefirst metatarsal 210 adjacent the proximal phalange to pivot toward thesecond metatarsal 292 and close angle 350, e.g., while the opposite endof the first metatarsal adjacent the medial cuneiform pivots away fromthe second metatarsal. This can also help avoid base compression betweenthe first and second metatarsals.

As discussed above with respect to FIGS. 19 and 20, a joint spacer 188can be positioned in a joint between a first metatarsal and a medialcuneiform before placing bone preparation guide 150 over the jointspacer. Bone preparation guide 150 can have an opening 170 (FIG. 5)sized to receive joint spacer 188. In some examples, opening 170 of bonepreparation guide 150 is size and/or shaped indexed to joint spacer 188such that there is substantially no, or no, relative movement betweenthe guide and spacer (once bone preparation guide 150 is placed overjoint spacer 188). This arrangement can ensure that bone preparationguide 150 is positioned precisely at the location where guided by jointspacer 188.

In practice, once bone preparation guide 150 is placed over joint spacer188, the guide slots of the bone positioning guide may not be perfectlyaligned with the ends of the bones (e.g., first metatarsal 210 andmedial cuneiform 220) to be cut through the guide slots. Accordingly, inother configurations, opening 170 of bone preparation guide 150 may notbe sized and/or shaped and/or indexed to joint spacer 188. In otherwords, opening 170 of bone preparation guide 150 may have a differentcross-sectional size and/or shape than the cross-sectional size and/orshape of joint spacer 188. In these configurations, bone preparationguide 150 may actuate or rotate about an axis extending through thelength of joint spacer 188. As a result, after the clinician places bonepreparation guide 150 over joint spacer 188, the clinician may rotatebone preparation guide 150 around joint spacer 188 until the guide slotsof the bone preparation guide are better aligned with the ends of thebones to be cut (e.g., first metatarsal 210 and medial cuneiform 220).Depending on the configuration of opening 170 of bone preparation guide150 and the configuration of joint spacer 188, the guide may rotatefreely (e.g., 360 degrees) around the joint spacer (e.g., seeker) orwithin a bounded angular range (e.g., from plus 20 degrees to minus 20degrees from a normal position).

FIG. 35 illustrates one example configuration of a joint spacer 188 thatcan allow bone preparation guide 150 to rotate around the spacer (e.g.,seeker). As shown in the illustrated example, joint spacer 188 has aproximal portion 370 having a cylindrical cross-section and a distalportion 372 having a rectangular cross-section. A leading edge of thedistal portion 372 is insertable into the joint between the firstmetatarsal 210 and the medial cuneiform 220. Once bone preparation guide150 is inserted over joint spacer 188, body 154 of the guide (FIG. 5)may be positioned about the proximal portion 370. This can allow theguide to be rotated around the proximal portion.

In other configurations, opening 170 of bone preparation guide 150 maybe size and/or shape indexed to the cross-sectional size and/or shape ofjoint spacer 188 but still provide relative rotation between the twocomponents. For example, opening 170 may have a circular cross-sectionsized and shaped to receive proximal portion 370 of joint spacer 188from FIG. 35. Because both opening 170 of bone preparation guide 150 andproximal portion 370 of joint spacer 188 have circular cross-sections insuch an embodiment, the two components may rotate relative to eachother. FIG. 36A is a perspective view of an example configuration ofbone preparation guide 150 having an opening 170 with circularcross-sectional shape. FIG. 36B is a perspective view of the examplebone positioning guide of FIG. 36A shown with joint spacer 188 from FIG.35 inserted into the guide.

In embodiments where bone preparation guide 150 can rotate relative tojoint spacer 188, the bone positioning guide and/or joint spacer mayinclude a locking mechanism that is engageable to lock the rotationalangle of the bone positioning guide relative to the joint spacer. Forexample, bone preparation guide 150 may include a set screw with thumbwheel that can be rotated, causing a distal end of the set screw to bearagainst or retract away from joint spacer 188. In use, a clinician canrotate bone preparation guide 150 around joint spacer 188 until theguide slots of the bone preparation guide are best aligned with the endsof the bones to be cut (e.g., first metatarsal 210 and medial cuneiform220). The clinician can then engage the locking mechanism to preventfurther rotation of bone preparation guide 150 relative to joint spacer188 before performing further steps of the procedure.

A bone correction procedure can be accomplished using one or moreinstruments according to the disclosure. In some applications, a bonecorrection procedure, such as a tarsal-metatarsal joint fusion procedureto correct a bunion deformity, is performed utilizing a fulcrum as apivot point. The first metatarsal is moved relative to a secondmetatarsal about the fulcrum without utilizing bone positioning guide10. In these applications, the clinician can insert the fulcrum into anintermetatarsal space between the first and second metatarsals andphysically grasp the first metatarsal and move the metatarsal about thefulcrum. For example, the clinician may directly grasp the firstmetatarsal with his hand or indirectly grasp the first metatarsalthrough an intermediate tool, such as a K-wire or pin inserted into thefirst metatarsal, a tenaculum or tongs, or other grasping instrument.Thereafter, the clinician may translate his hand relative to the foot ofthe patient being operated upon to move the first metatarsal about thefulcrum and relative to the second metatarsal, e.g., to anatomicallyalign the first metatarsal with respect to the second metatarsal.

FIG. 37 is a block flow diagram of an example bone correction techniqueutilizing a fulcrum. Specific steps of the technique of FIG. 37 can beperformed utilizing techniques and/or instruments discussed above. Asshown, the example technique of FIG. 37 includes mobilizing atarsal-metatarsal joint by releasing soft tissue and/or obstructing bone(500). After customary surgical preparation and access, the clinicianmay mobilize the tarsal-metatarsal joint by inserting a cuttinginstrument (e.g., saw, rotary bur, osteotome) at least partially betweenthe first metatarsal and medial cuneiform. The clinician may use thecutting instrument to release soft tissues and/or excise the plantarflare from the base of the first metatarsal. Excising the plantar flaremay involve cutting plantar flare off the first metatarsal so the faceof the first metatarsal is generally planar. In some applications, thedorsal-lateral flare of the first metatarsal may also be excised tocreate space for the correction procedure.

The technique of FIG. 37 further involves inserting a fulcrum betweenthe first metatarsal and the second metatarsal (502). The fulcrum may beinserted from the dorsal side of the foot toward the plantar side of thefoot in the intermetatarsal space between the first metatarsal and thesecond metatarsal. Although the fulcrum may be positioned at any desiredlocation in the intermetatarsal space, in some applications, the fulcrumis positioned adjacent to, and optionally in contact with, a proximalportion of the first metatarsal and/or the second metatarsal. Forexample, the fulcrum may be positioned adjacent to, and optionally incontact with, a proximal-most half of the first metatarsal and/orproximal-most half of the second metatarsal, such as the proximal-mostthird or proximal-most quarter of the first metatarsal and/or the secondmetatarsal. In one application, the fulcrum is positioned in theintermetatarsal space adjacent to, and optionally in contact with, thebase of the first metatarsal facing the medial cuneiform and the base ofthe second metatarsal facing the intermediate cuneiform. Thispositioning can help prevent or minimize lateral translation of the baseof the first metatarsal toward the base of the second metatarsal duringalignment of the first metatarsal. In some applications, the clinicianinserts the fulcrum from the dorsal toward the plantar side of the footin the intermetatarsal space and then translates the fulcrum proximallyin the intermetatarsal space.

The technique of FIG. 37 also involves preparing the end of the firstmetatarsal and/or the opposed end of the medial cuneiform (504).Typically, bone preparation is performed after inserting the fulcrum inthe intermetatarsal space (502), although bone preparation can beperformed prior to inserting the fulcrum. To prepare the end of thefirst metatarsal and the end of the medial cuneiform, a tissue removinginstrument can be applied to the ends of the bones. In one example, acutting instrument is applied to transect each bone and thereby form anew end surface, e.g., by inserting the cutting instrument through aslot defined bone preparation guide 150. Additionally or alternatively,the tissue removing instrument can be applied to the end face of eachbone to morselize at least a portion of the end face.

Independent of the specific technique used to prepare the end of thefirst metatarsal and/or the opposed end of the medial cuneiform (504),the technique of FIG. 37 includes moving the first metatarsal to helpcorrect the anatomical misalignment (506). The first metatarsal can bemoved relative to the second metatarsal before and/or after preparingthe end of the first metatarsal and/or the opposed end of the medialcuneiform. To move the first metatarsal relative to the secondmetatarsal, the clinician may directly or indirectly grasp the firstmetatarsal and translate a distal portion of the first metatarsal towardthe second metatarsal (e.g., a distal portion of the second metatarsal)in the transverse plane. As the distal end of the first metatarsal movestoward the second metatarsal in the transverse plane, the proximalportion of the first metatarsal can pivot about the fulcrum. Forexample, the fulcrum can function as a central point around which theproximal portion of the first metatarsal turns as the distal portion ofthe first metatarsal translates laterally. Accordingly, moving thedistal portion of the first metatarsal toward the second metatarsal canreduce the intermetatarsal space, and hence intermetatarsal angle,between the first metatarsal and the second metatarsal.

As the first metatarsal pivots in the transverse plane toward the secondmetatarsal, closing the intermetatarsal space, a proximal portion of thefirst metatarsal may contact and press against the fulcrum, therebycausing the fulcrum to contact and press against a proximal portion ofthe second metatarsal. The fulcrum may function to maintain spacingbetween the proximal portion of the first metatarsal and proximalportion of the second metatarsal, e.g., such a spacing equal to thewidth of the fulcrum. This may help reduce or eliminate shifting ortranslation of the base of the first metatarsal toward the base of thesecond metatarsal during pivoting.

In some applications of the technique of FIG. 37, the clinician mayrotate the first metatarsal in the frontal plane in addition to or inlieu of translating the first metatarsal in the transverse plane. Forexample, either before, after, or concurrent with moving the distalportion of the first metatarsal toward the second metatarsal in thefrontal plane, the clinician can directly or indirectly grasp the firstmetatarsal and rotate the metatarsal in the frontal plane. The clinicianmay rotate the first metatarsal about its longitudinal axis into ananatomically correct frontal plane position to correct a frontal planedeformity. Rotating the first metatarsal in the frontal plane mayfurther rotate the sesamoid bones (e.g., tibial sesamoid bone andfibular sesamoid bone) from a misaligned position to an aligned positionunder the first metatarsal. In some examples, the clinician additionallyor alternatively moves the first metatarsal in the sagittal plane tocorrect a misalignment in the sagittal plane.

In some applications of the technique of FIG. 37, the clinician movesthe first metatarsal in at least one plane from an anatomicallymisaligned position with respect to the second metatarsal to ananatomically aligned position. The at least one plane may be one or moreplanes selected from the frontal plane, the transverse plane, and thesagittal plane. For example, the clinician may move the first metatarsalin any two of the three planes or even in all three of the planes toadjust the first metatarsal from an anatomically misaligned position toan anatomically aligned position.

After suitably moving the first metatarsal relative to the secondmetatarsal, the joint between the first metatarsal and medial cuneiformmay be provisionally fixated (508). In one example, a fixation wire isdriven into the first metatarsal and the medial cuneiform toprovisionally fixate the joint. In another example, a compression pin,such as a threaded olive pin, is inserted through the first metatarsaland into the medial cuneiform to provide compression and provisionalfixation between the first metatarsal and the medial cuneiform. Thefulcrum can be removed from the intermetatarsal space before or afterprovisionally fixating the joint.

Following optional provisional fixation, the corrected position of thefirst metatarsal can be permanently fixated by fixing the position ofthe first metatarsal with respect to the medial cuneiform (510). One ormore bone plates can be applied across the tarsal-metatarsal joint andthe provisional fixation hardware removed. For example, a first boneplate may be positioned on a dorsal-medial region of the firstmetatarsal and on the medial cuneiform while a second bone plate ispositioned on a medial-plantar region of the first metatarsal and on themedial cuneiform. In these applications, the second bone plate may ormay not be a helical-shaped bone plate extending from a medial region ofthe medial cuneiform to a plantar region of the first metatarsal acrossthe joint.

FIG. 38 is a perspective view of a foot showing an example position of afulcrum during a bone correction procedure according to the method ofFIG. 37. As shown, fulcrum 356 is positioned in the intermetatarsalspace between the first metatarsal 210 and the second metatarsal 292. Inparticular, fulcrum 356 is illustrated as being positioned between aproximal portion of first metatarsal 210 adjacent base 352 and anopposed proximal portion of second metatarsal 292. An optional pin 512is inserted into the first metatarsal 210, providing a structure that aclinician can grab to move and manipulate the first metatarsal relativeto the second metatarsal. As discussed with respect to FIG. 37, theclinician may pivot the first metatarsal 210 about fulcrum 356 towardthe second metatarsal 292, reducing the intermetatarsal angle 350between the first and second metatarsals. The clinician may also rotatethe first metatarsal 210 in the frontal plane. The use of fulcrum 356can provide a pivot surface that also maintains a defined spacingbetween first metatarsal 210 and second metatarsal 292, potentiallyleading to a more anatomically correct realignment than when movingfirst metatarsal 210 without using the fulcrum.

As discussed above with respect to FIGS. 32 and 33, fulcrum 356 can havea variety of different configurations that provide a fulcrumfunctionality. FIGS. 39A and 39B illustrate another exampleconfiguration of fulcrum 356 that can be used according to thedisclosure. FIG. 39A is a perspective view of one side of fulcrum 356,while FIG. 39B is a perspective view of the fulcrum from the oppositeside. In the illustrated configuration, fulcrum 356 includes a body 380and a handle 382 operatively connected to the body. Typically, body 380and handle 382 will be formed as a unitary structure, e.g., by milling,casting, or molding the components to be permanently and structurallyintegrated together. However, body 380 and handle 382 may be fabricatedas separate components that are subsequently joined together.

Body 380 can be configured (e.g., sized and shaped) to be inserted intoan intermetatarsal space between adjacent metatarsals. For example, body380 may be configured to be inserted between a first metatarsal and asecond metatarsal. Body 380 is illustrated as having a rectangular shapewith a length 383 greater than its width 384 and thickness 386.Moreover, in this configuration, body 380 has a constant width 384across its length but has a thickness 386 that that tapers along atleast a portion of the length from the leading end 388 to the trailingend 390. For example, body 380 may have a tapered leading end 388 tofacilitate insertion of fulcrum 356 in a space between adjacentmetatarsals. In other configurations, body 380 may have a constantthickness across is length or may define a different generally polygonalshape (e.g., square, hexagonal) and/or generally arcuate shape (e.g.,circular, elliptical).

Fulcrum 356 in FIGS. 39A and 39B includes handle 382. Handle 382 canproject angularly away from body 380 to define a tissue retraction space392. Tissue retraction space 392 may be a region bounded on one side bybody 380 and one or more other sides by handle 382. In use, fulcrum 356may be inserted into an intermetatarsal space with handle 382 extendingout of the surgical incision and over an epidermal layer with tissuecaptured in tissue retraction space 392. For example, fulcrum 356 may beinserted into an intermetatarsal space with handle 382 projecting towardthe lateral side of the foot being operated upon. Tissue retractionspace 392 may help retract tissue and push the tissue laterally awayfrom a first metatarsal and/or medial cuneiform being operated upon.FIG. 40 illustrates fulcrum 356 in such an application with the fulcruminserted between a first metatarsal and a second metatarsal and handle382 extending toward the lateral side of the foot being operated upon.As shown, handle 382 pushes the skin of the foot away from the surgicalincision line, helping to provide access to the surgical site inaddition to providing fulcrum functionality.

With further reference to FIGS. 39A and 39B, handle 382 is illustratedas projecting laterally at a non-zero degree angle away from body 380.The specific angular orientation of the handle 382 relative to the body380 may vary. However, in some examples, handle 382 is oriented relativeto the body 380 so a handle axis 393 intersects an axis 394 extendingalong the length of the body at an acute angle 396 ranging from 20degrees to 75 degrees, such as 35 degrees to 55 degrees. Moreover,handle 382 may be composed of a single linear portion that intersectsbody 380 at a specific angular orientation or may be composed ofmultiple linear portions oriented at different angles relative to eachother.

In the illustrated example, handle 382 includes a grip portion 398 and ahandle body 402. The grip portion 398 can provide a surface that aclinician physically grips to insert fulcrum 356 into an intermetatarsalspace. For example, grip portion 398 may contain knurling or otheranti-friction surfacing texturing to allow the clinician to help gripthe fulcrum. Handle body 402 may be positioned between the body 380 offulcrum 356 and grip portion 398. Handle body 402 may or may not have areduced cross-sectional width compared to body 380 and/or grip portion398, as illustrated.

When configured with grip portion 398, the grip portion can be co-linearwith handle body 402 or may be offset relative to the handle body. Whengrip portion 398 is offset from handle body 402, a grip axis 404extending along the length of the grip portion may intersect the handleaxis 393 at an acute ranging from 20 degrees to 75 degrees, such as 35degrees to 55 degrees, although other angular arrangements can also beused. In the illustrated configuration, grip axis 404 is perpendicularto the axis 394 defined by body 380. Accordingly, when inserted into anintermetatarsal space, retracted tissue may be bounded by alaterally-facing side of body 380, by the lower surface of grip portion393, and in the dorsal-lateral direction by handle portion 392.

In some examples, the bone-contacting faces of body 380 are configuredto inhibit and/or facilitate relative motion between a bone and therespective bone-contacting face. With reference to FIG. 39A, body 380 offulcrum 356 has a first face 410, which may be positioned in contactwith a first metatarsal. First face 410 may have surface features whichallow the contacting metatarsal (e.g., first metatarsal) to rotate inthe frontal plane while contacting the face but inhibit movement of themetatarsal in the proximal to distal direction. The surface features maybe implemented as directionally-oriented ribs and/or grooves, which areillustrated in FIG. 39A as being multiple grooves extending lengthwiseacross body 380. By orienting the grooves lengthwise, the edges of thegrooves may have a tendency to engage or bite into the metatarsal if themetatarsal is moved proximally or distally, thereby inhibiting suchmovement. However, the grooves can allow the metatarsal to rotate in thefrontal plane against first face 410 without inhibiting such rotation.

Additionally or alternatively, the body 380 may have different surfacefeatures on the opposite face from first face 410. With reference toFIG. 39B, for example, body 380 of fulcrum 356 has a second face 412that is opposite first face 410. Second face 412 may have surfacefeatures that inhibit movement between fulcrum 356 and the contactingmetatarsal (e.g., second metatarsal) in the dorsal-to-plantar direction.The surface features may be implemented as directionally-oriented ribsand/or grooves. For example, in FIG. 39B, second face 412 is illustratedas having knurling, or a series of intersecting and overlapping ridges.FIG. 41 is perspective view of the second face 412 of fulcrum 356showing an alternative arrangement of surface features that may be used.In this alternative configuration, the surface features on second face412 are illustrated as being multiple grooves extending widthwise acrossbody 380. By orienting the grooves widthwise, the edges of the groovesmay have a tendency to engage or bite into the metatarsal if themetatarsal is moved plantarly or dorsally, thereby inhibiting suchmovement. The knurling illustrated on FIG. 39B can also achieve thisfunctionality.

In the configuration of FIGS. 39A and 39B, handle 382 includes gripportion 398 that can provide a surface a clinician physically grips toinsert fulcrum 356. In other configurations, handle 382 may beimplemented using a second fulcrum body that is a different size and/orshape than body 380. This arrangement can provide a clinician with asingle instrument having two functional ends, either one of which can beselected and used by the clinician, e.g., depending on thecharacteristics of the patient undergoing a surgical procedure.

FIGS. 42A and 42B are perspective and side views, respectively, of suchan example fulcrum 356 having two fulcrum bodies. As shown in thisexample, fulcrum 356 includes the body 380 and the handle 382 projectingat a non-zero degree angle away from the body. The body 380 provides afirst fulcrum body configured (e.g., sized and/or shaped) to be insertedinto an intermetatarsal space. In addition, handle 382 in this exampleis defined at least in part by a second fulcrum body 420. The secondfulcrum body 420 may also be configured (e.g., sized and/or shaped) tobe inserted into an intermetatarsal space. The first fulcrum body 380can differ from the second fulcrum 420 body by having a different sizeand/or shape.

In FIGS. 42A and 42B, the first fulcrum body 380 and the second fulcrumbody 420 are shown as having the same shape but different sizes. Inparticular, first fulcrum body 380 has a length 383, a thickness 386,and a width orthogonal to the length and thickness. Further, the secondfulcrum body 420 has a length 422, a thickness 424, and a widthorthogonal to the length and thickness. The thickness 422 of the secondfulcrum body 420 is illustrated as being greater than the thickness 386of the first fulcrum body 380. The length and width of the first andsecond fulcrum bodies 380, 420 are illustrated as being the same but maybe different in other examples (e.g., different width with same length,different length but same width, or different length and width).

In general, configuring the first fulcrum body 380 and second fulcrumbody 420 with different thicknesses can be useful to facilitate use indifferent sized intermetatarsal spaces. For example, the clinician mayselect one sized fulcrum body over the other sized fulcrum body based onthe anatomy (e.g., intermetatarsal space sizing) of the patientundergoing a surgical procedure. If the clinician determines uponbeginning to insert the selected fulcrum that the selected fulcrum isinappropriately sized, the clinician may retract the fulcrum, flip theinstrument, and insert the fulcrum on the opposite side of theinstrument.

While the first fulcrum body 380 and second fulcrum body 420 can beconfigured with a variety of different sizes, in some examples, eachfulcrum body has a thickness ranging from 0.5 millimeters to 12millimeters, such as from 1 millimeter to 10 millimeters, or from 1millimeter to 5 millimeters. The thickness 424 of the second fulcrumbody 420 may be at least 0.2 millimeters thicker than the thickness 386of the first fulcrum body, such as at least 0.5 millimeters thicker, atleast 1 millimeter thicker, or at least 2 millimeters thicker. In someexamples, first fulcrum body 380 and second fulcrum body 420 each have awidth within a range from 5 millimeters to 15 millimeters (e.g., about 6millimeters to about 10 millimeters) and a length ranging from 10millimeters to 30 millimeters, although other dimensions can be used.

In the illustrated example of FIGS. 42A and 42B, the first fulcrum body380 has a leading end 388 and a trailing end 390 and the second fulcrumbody 420 has a leading end 426 and a trailing end 428. In some examplesas shown, the leading end 388 of the first fulcrum body 380 and/or theleading end 426 of the second fulcrum body 420 has a thickness thattapers adjacent the leading end. This configuration can be useful tofacilitate insertion of a fulcrum body into an intermetatarsal space.When configured with a tapered leading end, the exemplary thicknessranges discussed above may be measured as the maximum thickness of thefulcrum body at any location along the length of the body.

When fulcrum 356 is implemented with first fulcrum body 380 and secondfulcrum body 420, the bone-contacting faces of one or both of thefulcrum bodies may be configured to inhibit and/or facilitate relativemotion between a bone and the respective bone-contacting face, asdiscussed with respect to FIGS. 39A, 39B, and 41. For example, a firstface 410 of first fulcrum body 380 and/or a first face 430 of secondfulcrum body 420 may have surface features which allow a contactingmetatarsal (e.g., first metatarsal) to rotate in the frontal plane whilecontacting the face but inhibit movement of the metatarsal in theproximal to distal direction, as discussed above. Similarly, a secondface 412 of first fulcrum body 380 and/or a second face 432 of secondfulcrum body 420 may have surface features that inhibit movement betweenfulcrum 356 and a contacting metatarsal (e.g., second metatarsal) in thedorsal-to-plantar direction, as also discussed above.

In the illustrated example, first fulcrum body 380 and second fulcrumbody 420 are oriented at a non-zero degree relative to each other andseparated by a handle body 402, e.g., of lesser cross-sectional width.For example, as discussed with respect to FIGS. 39A and 39B, handle 382may be oriented relative to first fulcrum body 380 such that handle axis393 intersects an axis 394 extending along the length of the body at anacute angle 396. When handle 382 includes the handle body 402 and thesecond fulcrum body 420, the second fulcrum body can be co-linear withhandle body 402 or may be offset relative to the handle body. Forexample, an axis 404 extending along the length of the second fulcrumbody may intersect the handle axis 393 at an acute angle 406 rangingfrom 20 degrees to 75 degrees, such as 35 degrees to 55 degrees, asdiscussed above.

In yet other configurations where fulcrum 356 is configured withmultiple ends of different dimensions, the ends may or may not beseparated by a separate handle body 402. For example, first fulcrum body380 and second fulcrum body 420 may be formed as a unitary structure(e.g., as opposed ends of a linear or curved unitary body).

FIGS. 43A and 43B are perspective and side views, respectively, of anexample multidimensional fulcrum having ends of different dimensions. Asshown, fulcrum 356 is composed of first fulcrum body 380 and secondfulcrum body 420 as discussed above with respect to FIGS. 42A and 42B.In the configuration illustrated in FIGS. 43A and 43B, however, thefirst fulcrum body 380 and the second fulcrum body 420 are integratedtogether to form a unitary fulcrum body having two opposed ends ofdifferent dimensions. As illustrated, the unitary fulcrum body has agenerally rectangular shape such that opposed ends of the fulcrum areseparated by a linear length of the body. However, the body may becurved or non-linear in alternative configurations. As discussed above,the first fulcrum body 380 and the second fulcrum body 420 forming therespective portions of the unitary body can have a variety of differentdimensions, and may or may not have surface features, to provide aclinician with a variety of fulcrum options in a single instrument.

Embodiments of the invention also include a disposable, sterile kit thatincludes an embodiment of a bone positioning guide and/or bonepreparation guide and/or fulcrum described herein. Other components thatmay be included within the sterile kit include bone fixation devices.

Thus, embodiments of the invention are disclosed. Although the presentinvention has been described with reference to certain disclosedembodiments, the disclosed embodiments are presented for purposes ofillustration, and not limitation, and other embodiments of the inventionare possible. One skilled in the art will appreciate that variouschanges, adaptations, and modifications may be made without departingfrom the spirit of the invention.

1. A method of correcting a bunion deformity comprising: inserting afulcrum between a first metatarsal and a second metatarsal, wherein thefirst metatarsal is anatomically misaligned with respect to the secondmetatarsal; preparing an end of the first metatarsal; preparing an endof a medial cuneiform opposing the end of the first metatarsal; andmoving a distal portion of the first metatarsal toward the secondmetatarsal in a transverse plane, thereby pivoting a proximal portion ofthe first metatarsal about the fulcrum and reducing an intermetatarsalangle between the first metatarsal and the second metatarsal.
 2. Themethod of claim 1, further comprising rotating the first metatarsal in afrontal plane.
 3. The method of claim 2, wherein rotating the firstmetatarsal further comprises rotating a tibial sesamoid bone and afibular sesamoid bone within the frontal plane.
 4. The method of claim2, further comprising moving the first metatarsal in a sagittal planewhile rotating the first metatarsal in the frontal plane and moving thedistal portion of the first metatarsal toward the second metatarsal inthe transverse plane.
 5. The method of claim 1, wherein inserting thefulcrum between the first metatarsal and the second metatarsal comprisespositioning the fulcrum in contact with both first metatarsal and thesecond metatarsal within an intermetatarsal space between the firstmetatarsal and the second metatarsal.
 6. The method of claim 5, whereinpositioning the fulcrum within the intermetatarsal space between thefirst metatarsal and the second metatarsal comprises positioning thefulcrum between the proximal portion of the first metatarsal and aproximal portion of the second metatarsal.
 7. The method of claim 1,wherein moving the distal portion of the first metatarsal toward thesecond metatarsal comprises moving the distal portion of the firstmetatarsal without causing the proximal portion of the first metatarsalto directly contact a proximal portion of the second metatarsal.
 8. Themethod of claim 1, wherein, when the first metatarsal is anatomicallymisaligned, the intermetatarsal angle is greater than 9 degrees, andreducing the intermetatarsal angle comprises reducing to an angle lessthan or equal to 9 degrees.
 9. The method of claim 1, wherein thefulcrum has a length extending from a leading end to a trailing end andtapers in thickness along at least a portion of the length from thetrailing end to the leading end.
 10. The method of claim 1, wherein thefulcrum has a generally rectangular cross-sectional shape or a generallycircular cross-sectional shape.
 11. The method of claim 1, wherein thefulcrum has a body and a handle operatively connected to the body, andthe handle projects at a non-zero degree angle from the body to define atissue retraction space between the handle and the body.
 12. The methodof claim 11, wherein the body has a first face on a side that the handleprojects away from and a second face on an opposite side that the handleprojects towards, inserting the fulcrum between the first metatarsal andthe second metatarsal comprises positioning the first metatarsal incontact with the first face and the second metatarsal in contact withthe second face, the first face has surface features configured toinhibit proximal to distal movement of the first face relative to thefirst metatarsal, and the second face has surface features configured toinhibit dorsal to plantar movement of the second face relative to thesecond metatarsal.
 13. The method of claim 1, further comprising, priorto inserting the fulcrum between the first metatarsal and the secondmetatarsal, selecting the fulcrum from a kit containing a plurality ofdifferent fulcrums varying in at least one of size and shape.
 14. Themethod of claim 1, wherein preparing the end of the first metatarsal andpreparing the end of the medial cuneiform occurs after moving the distalportion of the first metatarsal toward the second metatarsal.
 15. Themethod of claim 1, wherein preparing the end of the first metatarsal andpreparing the end of the medial cuneiform occurs after inserting thefulcrum.
 16. The method of claim 1, wherein preparing the end of thefirst metatarsal comprises at least one of cutting the end of the firstmetatarsal and morselizing the end of the first metatarsal, andpreparing the end of the medial cuneiform comprises at least one ofcutting the end of the medial cuneiform and morselizing the end of themedial cuneiform.
 17. The method of claim 1, further comprisingmobilizing a tarsal-metatarsal joint site between the first metatarsaland medial cuneiform by releasing soft tissue or obstructing bone. 18.The method of claim 1, further comprising, subsequent to moving thedistal portion of the first metatarsal toward the second metatarsal,fixing a position of the medial cuneiform with respect to the firstmetatarsal by applying at least one bone fixation device across orthrough a joint between the end of the first metatarsal and the end of amedial cuneiform.
 19. The method of claim 1, wherein moving the distalportion of the first metatarsal toward the second metatarsal comprisesmoving the distal portion of the first metatarsal with a clinician'shand without using an instrument.
 20. A method comprising: mobilizing atarsal-metatarsal joint site by releasing soft tissue or obstructingbone; inserting a fulcrum between a first metatarsal and a secondmetatarsal, wherein the first metatarsal is anatomically misaligned withrespect to the second metatarsal; preparing an end of the firstmetatarsal; preparing an end of a medial cuneiform opposing the end ofthe first metatarsal; moving a distal portion of the first metatarsaltoward the second metatarsal in a transverse plane, thereby pivoting aproximal portion of the first metatarsal about the fulcrum and reducingan intermetatarsal angle between the first metatarsal and the secondmetatarsal; provisionally fixating a joint between the end of the firstmetatarsal and the end of the medial cuneiform; and fixing the positionof the first metatarsal with respect to the medial cuneiform by applyingat least one bone fixation device across or through the joint betweenthe end of the first metatarsal and the end of the medial cuneiform. 21.The method of claim 20, further comprising rotating the first metatarsalin a frontal plane.
 22. The method of claim 21, wherein rotating thefirst metatarsal further comprises rotating a tibial sesamoid bone and afibular sesamoid bone within the frontal plane.
 23. The method of claim20, wherein moving the distal portion of the first metatarsal toward thesecond metatarsal comprises moving the distal portion of the firstmetatarsal without causing the proximal portion of the first metatarsalto directly contact a proximal portion of the second metatarsal.
 24. Themethod of claim 20, wherein the fulcrum has a body and a handleoperatively connected to the body, and the handle projects at a non-zerodegree angle from the body to define a tissue retraction space betweenthe handle and the body.
 25. The method of claim 24, wherein the bodyhas a first face on a side that the handle projects away from and asecond face on an opposite side that the handle projects towards,inserting the fulcrum between the first metatarsal and the secondmetatarsal comprises positioning the first metatarsal in contact withthe first face and the second metatarsal in contact with the secondface, the first face has surface features configured to inhibit proximalto distal movement of the first face relative to the first metatarsal,and the second face has surface features configured to inhibit dorsal toplantar movement of the second face relative to the second metatarsal.26. The method of claim 20, further comprising, prior to inserting thefulcrum between the first metatarsal and the second metatarsal,selecting the fulcrum from a kit containing a plurality of differentfulcrums varying in at least one of size and shape.
 27. A fulcrum foruse in a bone realignment procedure comprising: a body configured to beinserted in an intermetatarsal space between adjacent metatarsals, and ahandle operatively connected to the body, wherein the handle projects ata non-zero degree angle from the body to define a tissue retractionspace between the handle and the body.
 28. The fulcrum of claim 27,wherein the handle includes a grip portion and a handle body positionedbetween the body of the fulcrum and the grip portion.
 29. The fulcrum ofclaim 27, wherein the body defines an axis extending along the length ofthe body, the handle defines a handle axis projecting at the non-zerodegree angle from the body, and an angle between the axis of the bodyand the handle axis ranges from 20 degrees to 75 degrees.
 30. Thefulcrum of claim 29, wherein the angle ranges from 35 degrees to 55degrees.
 31. The fulcrum of claim 27, wherein the handle includes a gripportion and a handle body positioned between the body of the fulcrum andthe grip portion; the handle axis is defined by the handle body; thegrip portion defines a grip axis, and an angle between the grip axis andthe handle axis ranges from 20 degrees to 75 degrees.
 32. The fulcrum ofclaim 31, wherein the grip axis is perpendicular to the axis defined bythe body of the fulcrum.
 33. The fulcrum of claim 27, wherein the bodyand the handle are formed as a unitary structure.
 34. The fulcrum ofclaim 27, wherein the body is configured to be inserted between a firstmetatarsal and a second metatarsal.
 35. The fulcrum of claim 27, whereinthe body configured to be inserted in the intermetatarsal space is afirst body, and the handle defines a second body also configured to beinserted in the intermetatarsal space, the first body and the secondbody varying in size.
 36. The fulcrum of claim 35, wherein the firstbody has a maximum thickness, the second body has a maximum thickness,and the maximum thickness of the first body is less than the maximumthickness of the second body.
 37. The fulcrum of claim 36, wherein thefirst body extends from a leading end to a trailing end and the leadingend of the first body is tapered, and the second body extends from aleading end to a trailing end and the leading end of the second body istapered.
 38. The fulcrum of claim 27, wherein the body has a first faceon a side that the handle projects away from and a second face on anopposite side that the handle projects towards, the first face hassurface features configured to inhibit proximal to distal movement ofthe first face along a metatarsal against which the first face ispositioned, and the second face has surface features configured toinhibit dorsal to plantar movement of the second face along a metatarsalagainst which the second face is positioned.
 39. The fulcrum of claim38, wherein the first face has multiple grooves extending lengthwiseacross the body, and the second face has at least one of knurling andmultiple grooves extending widthwise across the body.
 40. The fulcrum ofclaim 27, wherein the body is rectangular shaped.
 41. The fulcrum ofclaim 40, wherein the body extends from a leading end to a trailing end,the handle projects off the trailing end, and the leading end istapered.
 42. A multidimensional fulcrum comprising: a fulcrum bodyhaving a length extending from a first end to a second end, a width, anda thickness, wherein the first end of the fulcrum has a first thicknessand is configured to be inserted into an intermetatarsal space betweenadjacent metatarsals of a first size, the second end of the fulcrum hasa second thickness and is configured to be inserted into anintermetatarsal space between adjacent metatarsals of a second size, andthe second thickness is greater than the first thickness.
 43. Thefulcrum of claim 42, wherein the first thickness and the secondthickness each fall within a range from 1 millimeter to 10 millimeters,and the second thickness is at least 1 millimeter greater than the firstthickness.
 44. The fulcrum of claim 42, wherein the first end if taperedand the second end is tapered.
 45. The fulcrum of claim 42, wherein thefulcrum body has a rectangular shape.